<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title></title>
</head>
<body>
<div id="app">
  <h1>{{message}}</h1>

</div>
</body>
<script type="module">
  import {createApp,ref} from "../../../../../js/vue.esm-browser.js";

  const app = createApp({
    setup(){

      let message = ref("Hello world")
      // 使用ref
      return {
        message
      }
    }
  })
  app.mount("#app")

</script>
</html>